Metal molded body manufacturing apparatus by electromagnetic stirring

ABSTRACT

There is provided a metal molded body manufacturing apparatus for electromagnetically stirring metallic molten metal and molding a metal molded body. The metal molded body manufacturing apparatus includes: a die having an inclined side wall; and a moving magnetic field generation section that stirs the molten metal in the die, wherein the moving magnetic field generation section includes a magnetic body, and a coil wound around the magnetic body as a center, and an end surface of the magnetic body is disposed in parallel to an inner surface of the side wall.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an apparatus for manufacturing a metalmolded body by stirring molten metal in a die.

Description of Related Art

Conventionally, as one of technologies for molding aluminum alloy or thelike, a die casting method for pressurizing and injecting molten metalinto a die to obtain a molded article having a predetermined shape isused, and in a case where molten metal is used, problems, such as ashort life of the die, insufficient quality of a product due togeneration of shrinkage, mold cavity, or the like, are pointed out.

Additionally, conventionally, as a method for molding a metal moldedbody while stirring molten metal in a die, and a method for furthermachining an obtained metal molded body by a press machine, arheocasting process is known. In this case, the die is generallyprovided with a draft angle, and therefore work for extracting amanufactured metal molded body to transpose the metal molded to amolding die such as a press machine in a next process is easy. Ofcourse, the metal molded body is sometimes used as a product withoutchange.

Furthermore, an aluminum structure used in a vehicle body or the like isoften thin and long, and is bent. In a case where such a thin and longstructure is molded with aluminum, the shape of a stirring die is madeto be thin and long in order to approximate the shape of a metal moldedbody before press molding into the structure.

JP 5352236 B1, JP 2009-74103 A, and JP 2007-144501 A each describe anapparatus for performing electromagnetic stirring for molten metal. Aninner peripheral surface of a melting furnace (pot) of the apparatus isformed in a cylindrical shape, and molten metal is stirred along thecircular inner peripheral surface.

In addition, an apparatus described in JP 2006-289448 A is used for acontinuous casting facility, and linear type electromagnetic stirringapparatuses are provided on an outside so as to face both linear sidewalls.

Additionally, JP 2006-289448 A and JP 2006-289476 A each disclose astructure of a linear type electromagnetic stirring apparatus.

Furthermore, for example, relation between a gap and electromagneticforce is considered in “Electromagnetic Coil Designed byMagneto-Hydro-Dynamic Simulation, shinnittetsu giho vol. 379”, and“Development of a Simulation Model for Electromagnetic Stirring inMelting Furnace, Furukawa-sky Review No. 3, 2007”.

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

Molten metal which is put into a die generally starts cooling from amoment of this putting. Therefore, time for stirring until the moltenmetal is solidified is about 10 seconds at most. That is, it isimportant to how efficient the molten metal is stirred for a short timeuntil the molten metal is solidified.

Herein, the above die is provided with the draft angle for extractingthe manufactured metal molded body.

However, thrust of electromagnetic stirring which acts on the moltenmetal is significantly changed at a position in the depth direction inthe die, depending on this draft angle. For example, as illustrated inFIG. 1B, when an effective gap G2 at a lower end of the die is twice aneffective gap G1 at an upper end of the die, magnetic flux density isabout 30%, there is a possibility that the thrust falls to ten percent(square of 0.3) (refer to “Electromagnetic Coil Designed byMagneto-Hydro-Dynamic Simulation, shinnittetsu giho vol. 379”, and“Development of a Simulation Model for Electromagnetic Stirring inMelting Furnace, Furukawa-sky Review No. 3, 2007”). Therefore, a largedifference in thrust is generated between the upper end and the lowerend of the die, and efficiency of stirring becomes low in the vicinityof the lower end.

The difference in thrust cannot be ignored, when the stirring time ofabout 10 seconds 10 is considered. In addition to the above,particularly, in a case of the metal molded body of such a thin andlong, and bent structure as to be used for a vehicle body or the like,the shape of the die is shapeless or is not a usual shape, and has abranch section or the like in the middle. The shape of such a die is oneof causes of hindering a flow of stirring, and cannot be ignored in viewof efficiency of stirring, along with the gap of the draft angle asdescribed above, when all the stirring processes for about 10 secondsare considered,

Therefore, an object of the present invention is to provide a metalmolded body manufacturing apparatus capable of efficiently stirringmolten metal.

Means to Solve the Problem

(1) A metal molded body manufacturing apparatus of the present inventionis a metal molded body manufacturing apparatus for electromagneticallystirring molten metal, and molding a metal molded body, the metal moldedbody manufacturing apparatus including: a die including a side wallhaving an inclined inner surface; and a moving magnetic field generationsection that is disposed along an outer periphery of the die, and stirsthe molten metal in the die, wherein the moving magnetic fieldgeneration section includes a magnetic body, and a coil wound around themagnetic body as a center, and an end surface of the magnetic body isdisposed such that a gap between the end surface of the magnetic bodyand the inner surface of the side wall becomes uniform.

Herein, “the gap between the end surface of the magnetic body and theside wall inner surface is uniform” means that the end surface of themagnetic body of the moving magnetic field generation section isparallel to the inner surface of the side wall, and is a conceptincluding a case where the end surface of the magnetic body is notparallel to an outer face.

Furthermore, the metal molded body is a concept including metal that isobtained by cooling molten metal to be brought into a solid-liquidcoexistent state, includes metal that is further cooled to besolidified, including metal that is obtained by further heating solidmetal to be brought into a solid-liquid coexistent state, and includinga primary molded body that is machined in a next process to become aproduct, and a final molded body that becomes a product without change.

(2) In such a metal molded body manufacturing apparatus, an inclinationof the side wall inner surface preferably serves as a draft angle forextracting the metal molded body.

(3) The draft angle is preferably 1° to 9°.

(4) The side wall preferably has a pair of facing walls that face eachother, the moving magnetic field generation section is preferablyprovided along each of the facing walls, and the moving magnetic fieldgeneration sections preferably generate respective moving magneticfields in reverse directions from each other so as to generate a vortexin the molten metal.

(5) The metal molded body manufacturing apparatus preferably furtherincludes: a base; an inclined plate to which the moving magnetic fieldgeneration section is fixed; and an inclination adjusting mechanism thatadjusts an inclination of the inclined plate to the base so as touniform the gap between the end surface of the magnetic body and theside wall inner surface, the inclination adjusting mechanism beingdisposed between the inclined plate and the base.

(6) The end surface of the magnetic body of the moving magnetic fieldgeneration section preferably extends beyond an upper surface of themolten metal put into the die from below a bottom of the die.

(7) The die preferably has a curved shape in plan view, an additionalmagnetic body member is preferably provided in the end surface of themagnetic body of the moving magnetic field generation section, and anend surface of the additional magnetic body member is preferably acurved surface along the curved inner surface of the die.

Effect of the Invention

(1) In the metal molded body manufacturing apparatus of the presentinvention, the end surface of the moving magnetic field generationsection is disposed in parallel to the inclined inner wall surface ofthe die, and the gap (distance) between this end surface and the innersurface of the die is made the same, and therefore a difference ofthrust in the vertical direction of the wall surface is unlikely to begenerated.

Therefore, while the molten metal is stirred by a die having a shapeclose to a final product, residual gas is discharged, and growth of acrystal is prevented, the molten metal can be isothermally cooled as awhole to be solidified.

(2) In such a manufacturing apparatus for the metal molded body, in acase where the inclination of the side wall serves as the draft anglefor extracting the metal molded body, the metal molded body can beeasily extracted, which is effective.

Additionally, the draft angle is provided, and therefore the penetrationdepth of the moving magnetic field approaches the center of the dietoward a lower surface of the die. Therefore, a strong vortex generatescloser to the center toward the lower surface of the die, and a downwardflow which draws the molten metal from the upper surface generates.Dislocation (convection) of an upper layer and a lower layer of themolten metal proceeds by this vortex to facilitate discharge of residualgas.

(3) In a case where the draft angle is 1° to 9°, such an angle is easyto use as the draft angle. In addition, the convection can be generated.

(4) In a case where the side wall has a pair of the facing walls thatface each other, the moving magnetic field generation section isprovided along each of the facing walls, and these moving magnetic fieldgeneration sections generate respective moving magnetic fields inreverse directions from each other so as to generate a vortex in themolten metal, it is possible to enhance efficiency of stirring even inan oblong die.

Additionally, growth of a metal crystal is hindered by the vortex,resulting in a dense structure.

(5) In a case where the metal molded body manufacturing apparatusfurther includes a base, an inclined plate to which the base and themoving magnetic field generation section are fixed and the inclinationadjusting mechanism that adjusts inclination of the inclined plate tothe base such that the end surface of the magnetic body are parallel tothe side wall, the inclination adjusting mechanism being disposedbetween the inclined plate and the base, the inclination of the movingmagnetic field generation section can be adjusted to the draft anglewhen the draft angle of the die is changed.

(6) In a case where the end surface of the magnetic body of the movingmagnetic field generation section extends beyond the upper surface ofthe molten metal put into the die from below the bottom of the die, thewhole of the molten metal can be reliably moved, and therefore stirringefficiency is high.

(7) In a case where the die has the curved shape in plan view, theadditional magnetic body member is provided in the end surface of themagnetic body of the moving magnetic field generation section, and theend surface of the additional magnetic body member is the curved surfacealong the curved inner surface of the die, it is possible to form asmooth flow along the curved surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a sectional view illustrating a metal molded bodymanufacturing apparatus according to an embodiment of the presentinvention, and FIG. 1B is a sectional view illustrating an example forcomparison with the apparatus of FIG. 1A.

FIG. 2A is a plan view illustrating of a die according to theembodiment, and FIG. 2B is a sectional view taken along a A-A of the dieof FIG. 2A.

FIG. 3 is a schematic plan view illustrating moving magnetic fieldgeneration sections and the die.

FIG. 4A and FIG. 4B each are a schematic view illustrating a state wherea coil is wound around a core back.

FIG. 5A and FIG. 5B each are a schematic view illustrating a state wherethe coil is wound between slots.

FIG. 6 is a side view illustrating a metal molded body manufacturingapparatus according to another embodiment.

FIG. 7A is a front view illustrating a moving magnetic field generationsection according the other embodiment and FIG. 7B is a bottom view ofthe moving magnetic field generation section of FIG. 7A.

FIG. 8 is a plan view illustrating a manufacturing apparatus accordingto yet another embodiment.

FIG. 9A is a plan view illustrating a state where an additional magneticbody is detached from the moving magnetic field generation section ofFIG. 8, and FIG. 9B is a plan view of an additional magnetic body memberof FIG. 8, and FIG. 9C is a plan view illustrating an additionalmagnetic body member according to another embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Embodiment 1.Summary

A manufacturing apparatus for a metal molded body of the presentinvention (hereinafter simply referred to as a manufacturing apparatus)will be described with reference to FIG. 1. A manufacturing apparatus 1illustrated in FIG. 1 is an apparatus that stirs molten metal, which isput into a die 2, by moving magnetic field generation sections 3, andmolds a metal molded body in the die.

The metal molded body manufactured by this manufacturing apparatus 1 issubjected to machining for making a press-formed or press-molded articleby, for example, a press apparatus (not illustrated) in a next process,or is used as a final molded body without change.

2. Manufacturing Apparatus 1

More specifically, the manufacturing apparatus 1 includes the die 2having a side wall 5 having an inclined inner surface, and a movingmagnetic field generation section 3 that stirs the molten metal in thedie 2. An end surface 3 a of a magnetic body of the moving magneticfield generation section 3 is disposed such that a gap G (refer to FIG.1A) with an inner surface 5 c of the side wall (hereinafter referred toas an inner wall surface) becomes uniform. The end surface 3 a and theinner wall surface 5 c are parallel or substantially parallel to eachother.

(As to Die 2)

The die 2 is preferably formed of, for example, a material having lowmagnetic permeability and a higher melting point than that of the moltenmetal which is metal put into the die. In this embodiment, stainlesssteel is used.

The die 2 (refer to FIG. 2B) has a bottom 4, and a side wall 5 extendingupward from a peripheral edge of the bottom 4. The side wall 5 inclinesoutward toward an opening side so as to extract the metal molded body.The thickness of the side wall 5 is generally uniform, but may not beuniform. In a case where the thickness is not uniform, at least theinner surface only needs to incline outward toward the opening side. Theangle of the inclination only needs to be a draft angle for extractingthe metal molded body to an axis of the die 2 (an axis perpendicular toa surface of the bottom, or a vertical axis). For example, the draftangle is 1° to 9°, and preferably 5° to 7°.

(Shape of Die)

As illustrated in FIG. 2A, in this embodiment, the die 2 has, forexample, a long oval shape or an athletics track shape in plan view.That is, the side wall 5 of the die 2 includes a pair of facing walls 5a, 5 a facing each other. Respective both ends of the straight facingwalls 5 a, 5 a are connected to the semicircular sections 5 b, 5 b, sothat the above long oval shape or athletics track shape is formed.

FIG. 2B illustrates a sectional view of FIG. 2A. The side wall 5inclines so as to expand toward the opening side. In this embodiment,the bottom 4 is flattened.

(Molten Metal)

The molten metal which is put into the die 2 is metal such as aluminumalloy that is melted.

(Moving Magnetic Field Generation Section 3)

Returning to FIG. 1A, the moving magnetic field generation sections 3each include, for example, a magnetic body 6 (hereinafter referred to asa core), and coils 7 wound around the core 6 as a center. As illustratedin FIG. 1A, the moving magnetic field generation sections 3, 3 (refer totwo-dot chain lines of FIG. 2A) are disposed such that the end surfacesof the cores 6 are parallel to the inner surfaces of the facing walls 5a, 5 a of the side wall and there is clearances between the end surfacesof the core 6 and the outer surfaces of the side wall.

The end surfaces of the cores 6 of the moving magnetic field generationsections 3 each extend from a position below the bottom 4 of the die 2to a position above an upper surface of the molten metal put into thedie. Therefore, it is possible to reliably move the whole of the moltenmetal.

(Magnetic Bodies 6 and Coils 7)

Returning to FIG. 1A, the magnetic bodies 6 and the coils 7 areconventionally known ones. For example, each magnetic body 6 employs,for example, a silicon steel sheet, and is formed by stacking thinsheets because of reduction in influence of an eddy current or the like.

In each magnetic body 6, a plurality of slots 8 are formed on the sidewall side of the die 2 at equal intervals (refer to FIG. 4A). Each slot8 has a coil 7 wound therearound.

(Principle and the Like)

FIG. 3 schematically illustrates the manufacturing apparatus 1. In thefigure, the three moving magnetic field generation sections 3 are linedto be connected on one side of the die 2. A power source is athree-phase alternating current (AC). Three-phase ACs U, W, V aresequentially applied to coils of terminal symbols R, S, T. Then, amagnetic field (direction of an arrow H) that moves in parallel to thefacing wall 5 a of the side wall 5 is generated in the die 2.Specifically, a +U-phase current, a −W-phase current, a +V-phasecurrent, a −U-phase current, a +W-phase current, and a −V-phase currentare applied to the respective coils 7 illustrated in FIG. 3 in thisorder from the left of the figure. In these three-phase ACs, phases ofthe +U-phase, the +V-phase, and the +W-phase are AC currents shifted by120° in order, and currents of the −V-phase, the −W-phase, and the−U-phase are opposite directions. As to the current flow direction, itis defined that the flow direction from the front to the back of thepaper sheet is positive. When a current flows in the positive direction,a clockwise magnetic flux with the coil as the center generates, andwhen a current flows in the reverse direction, a counterclockwisemagnetic flux generates. The magnitude of the magnetic flux densityincreases as a current value of the coil increases.

Accordingly, when a current is applied to the coil, a combined magneticflux density distribution moves from the left to the right (see an arrowφ) with lapse of time. That is, a moving magnetic field that moves fromthe left to the right along the longitudinal direction of the core 6 isformed. Consequently, an induced current is generated in the moltenmetal, and an electromagnetic force (Lorentz force) is generated in themolten metal. Then, driving force (refer to arrows H1, H2, H3) thatprovides flows to follow the motion of the moving magnetic field isapplied in the molten metal.

Symbol O denotes a neutral point.

FIG. 4A is a plan view of the moving magnetic field generation section 3of FIG. 1A. A winding method illustrated in the figure is a core backwinding method. The cores 6 of the moving magnetic field generationsections 3 each are formed in a comb-tooth shape, and the coils 7 arewound between the teeth of each core (the above slots 8).

The slots are filled with the coils (coil conductors) 7. Each core 6 iscomposed of a rectangular column shaped yoke (core back) 6 a, and teeth9 each having an end fixed to dovetail-shaped grooves 6 b formed in theyoke. The number of the teeth 9 is seven, the number of the coils 7 tobe wound around the yoke between the teeth is six, and all the coils arewound in the same direction. Therefore, in a case where a current entersfrom an initially wound coil, and a case where a current enters from afinally wound coil, the polarities are reverse. Each slit 8 a that isopened toward the die 2 is formed between the adjacent teeth 9, 9. Theyoke 6 a and the teeth 9 are each formed of a core formed bysuperimposing a large number of thin sheets of silicon steel sheets, andthese may be integrated.

In the moving magnetic field generation section 3, as a minimum unit forsmoothly generating a moving magnetic field by a three-phase powersupply, the six slots 8 are used as the minimum unit. In a case wherethe further reduced number of the slots is used as the minimum unit,balance is kept by mutual magnetic coupling.

FIG. 5A illustrates a moving magnetic field generation section 3according to another embodiment. A winding method illustrated in thefigure is an inter-slot winding method. A U-phase coil passes through aleftmost slot and a fourth slot so that the coil is wound around threeteeth between the leftmost slot and the fourth slot. Similarly, aV-phase coil passes through a second slot and a fifth slot so that thecoil is wound around three teeth between the second slot and the fifthslot. A W-phase coil passes through a third slot and a sixth slot sothat the coil is wound around three teeth between the third slot and thesixth slot. These three kinds of coils are overlapped to intersect witheach other on the lateral side of the core 6, as illustrated in FIG. 5B.

In this method, the coils 7 do not wound around a core back 6 a, andtherefore the core back 6 a can be used to fix the moving magnetic fieldgeneration section 3.

Conclusion

Returning to FIG. 1A, the moving magnetic field generation sections 3are disposed such that the end surfaces of the cores 6 are parallel tothe inner surface of the side walls inclining at draft angle. Therefore,a difference in thrust in the vertical direction of the side walls isunlikely to be generated. That is, the whole of a material along thewall surfaces flows, and therefore stirring efficiency is high, growthof crystals is prevented. As illustrated in FIG. 2A, a pair of themoving magnetic field generation sections 3, 3 generate moving magneticfields in the reverse directions from each other so as to generate avortex in the molten metal, and therefore stirring efficiency is high.

Second Embodiment 3. Another Embodiment

Now, FIG. 6 illustrates a manufacturing apparatus according to anotherembodiment. The manufacturing apparatus 10 includes a base 11 installedon a floor surface of a building such as a factory, and inclined plates12, which are provided in the base 11, and to which the moving magneticfield generation sections 3 are fixed. The two inclined plates are usedas one set, and are provided with the respective moving magnetic fieldgeneration sections 3. These inclined plates 12, 12 are disposed so asto face each other. In the base 11, inclination adjusting mechanisms 13that adjust the inclination of the inclined plates 12 are provided.

(Base 11, Inclined Plates 12, Inclination Adjusting Mechanisms 13)

The base 11 includes a base plate 11 a installed on the floor surface, aplacing stand 11 b that is erected from the vicinity of a center of thebase plate 11 a, and allows a die 2 to be placed on an upper surfacethereof, and a pair of supporting sections 11 c, 11 c erected from thebase with the placing stand 11 b therebetween.

The inclined plates 12 each are a flat plate shape, and formed of metalsuch as stainless steel. Each inclined plate is rockingly pivoted to thevicinity of an upper end of the supporting section 11 c. A shaft of therocking is a shaft 12 a parallel to a longitudinal axis of the die 2.

The inclination adjusting mechanisms 13 each include a screw mechanism13 a. The screw mechanism 13 a is disposed below the shaft 12 a. In thescrew mechanism 13 a, a male screw member is screwed in the female screwmember provided in the supporting section 11 c toward the inclined plate12, so that a lower part of the inclined plate 12 is pressed, and theinclined plate 12 is rotated about the shaft 12 a as a rotation center.

In each inclination adjusting mechanism 13, the moving magnetic fieldgeneration section 3 can be disposed such that an end surface of thecore 6 is parallel to an inner surface 5 c of the side wall by changingthe inclination of the inclined plate 12. Therefore, a difference inthrust is unlikely to be generated in molten metal in the verticaldirection of the side wall. The whole of the material along the wallsurfaces flows, and therefore growth of metal crystals is prevented, andminute metal molded body is formed.

In the manufacturing apparatus 10, moving mechanisms 14 that allow thesupporting sections 11 c to be freely movable to the bases plate 11 amay be provided. As the moving mechanism 14 (two-dot chain lines),conventionally known mechanisms such as slide mechanisms can be used. Byuse of the moving mechanisms 14, the inclined plates 12 are broughtcloser to or away from the side wall 5, that is, are moved with paralleltranslation to adjust the gaps.

As the manufacturing apparatus 10, both the moving mechanisms 14 and theinclination adjusting mechanisms 13 are preferably provided.

(Transposing Mechanism of Laminar Flow)

For example, as illustrated in FIG. 7A and FIG. 7B, a moving magneticfield generation section 15 that generates a inclined vertical flow Pcan be used. In this case, the inclined vertical flow is generated inmolten metal, and molten metal in upper and lower layers in a die istransposed. Consequently, residual gas venting is facilitated, moreefficient stirring is attained, and therefore it is possible to makecrystal grains fine.

More specifically, in the moving magnetic field generation section 15,slits 8 b obtained by inclining (skewing) two central slits in theadvancing direction from a bottom to a top are formed. Consequently,coil end portions are the same appearance as a general coil end, andtherefore there is no waste in assembling appearance.

As the shape of the bottom of the die 2, a hemispherical bottom forsmoothly reversing a downward flow of axially moving molten metal 1 toan upward flow is preferably provided (not illustrated). Referencenumeral 8 c in FIG. 7B denotes a wedge or plate for holding the coil 7in the slot 8.

Third Embodiment

FIG. 8 illustrates a manufacturing apparatus according to anotherembodiment. This embodiment includes a large number of parts which arethe same as the parts described in the above embodiments, and thereforethe same parts are denoted by the same reference numerals, anddescription thereof will be omitted.

A manufacturing apparatus 16 illustrated in FIG. 8 includes a die 17having an inverted T-shape in plan view, and a plurality of pairs of themoving magnetic field generation sections 3 disposed along a wallsurface of the die so as to sandwich the die 17.

Near a root of the T shape of the die 17, curved side walls 17 a havingcurved inner surfaces are provided. In this embodiment, moving magneticfield generation sections 18 having curved surfaces parallel to thecurved inner surfaces are provided so as to face the curved innersurfaces of the curved side walls 17 a in order to maintain uniformgaps. Additional magnetic body members 19 are provided on end surfacesof cores 7 of the moving magnetic field generation sections 18. Endsurfaces 19 a of the additional magnetic body members are curvedsurfaces along the curved side walls 17 a of the die 17. The additionalmagnetic body members 19 are mounted on teeth 9 of cores 6 that generatemagnetic fields, are designed so as to be parallel to the inner surfacesof the curved side walls 17 a by magnetically extending the teeth 9.

A moving magnetic generation section of this embodiment includes twelvemoving magnetic field generation sections 3 provided on liner parts, andthe two moving magnetic field generation sections 18 provided atcorners. Thus, the moving magnetic field generation section is divided,and two kinds of the moving magnetic field generation sections arefurther combined and disposed, so that it is possible to correspond tovarious shaped of dies. Consequently, it is possible to uniformly stirmolten metal in various shaped dies (refer to arrows in the figure).

Now, details of the curved moving magnetic field generation sections 18will be described with reference to FIG. 9A and FIG. 9B. FIG. 9Aillustrates a state where an additional magnetic body member 19 isdetached from the moving magnetic field generation section 18 of FIG. 8.Insertion ports 18 a are formed in distal end surfaces (surfaces facingthe side wall of the die) of the teeth 9 of the moving magnetic fieldgeneration section in FIG. 9A. On the other hand, as illustrated in FIG.9B, insertion sections 19 b that slide to be inserted into the insertionports 18 a are formed in proximal end surfaces of the additionalmagnetic body member 19. The additional magnetic body member 19 isfreely engaged and disengaged by sliding. Therefore, an additionalmagnetic body member in accordance with a curved shape of a die onlyneeds to be prepared with respect to the single moving magnetic fieldgeneration sections 18 as a base, and therefore this configuration iseconomical.

FIG. 9C illustrates an additional magnetic body member 20 having arecessed curved surface.

The additional magnetic body member may be curved in the heightdirection (not illustrated).

4. Modification

As a material of the die 2, metal having heat resistance withstanding ofthe high temperature of molten metal, and having magnetic permeability(for example, stainless steel), ceramics, and the like can be used.

The die may have a shape such as an arc shape or a forked shape in planview.

The upper part of the die 2 is opened in this embodiment, but may beclosed by an openable lid. In this case, the lid is opened, and moltenmetal is put into the die or extracted a metal molded body.

1. A metal molded body manufacturing apparatus for electromagneticallystirring metallic molten metal and molding a metal molded body, themetal molded body manufacturing apparatus comprising: a die including aside wall having an inclined inner surface; and a moving magnetic fieldgeneration section that is disposed along an outer periphery of the die,and stirs the molten metal in the die, wherein the moving magnetic fieldgeneration section includes a magnetic body, and a coil wound around themagnetic body as a center, and an end surface of the magnetic body isdisposed such that a gap between the end surface of the magnetic bodyand the inner surface of the side wall becomes uniform.
 2. The metalmolded body manufacturing apparatus according to claim 1, wherein aninclination of the side wall serves as a draft angle for extracting themetal molded body.
 3. The metal molded body manufacturing apparatusaccording to claim 2, wherein the draft angle is 1° to 9°.
 4. The metalmolded body manufacturing apparatus according to claim 1, wherein theside wall has a pair of facing walls that face each other, the movingmagnetic field generation section is provided along each of the facingwalls, and the moving magnetic field generation sections generaterespective moving magnetic fields in reverse directions from each otherso as to generate a vortex in the molten metal.
 5. The metal molded bodymanufacturing apparatus according to claim 1, further comprising: aninclined plate to which a base, and the moving magnetic field generationsection are fixed; and an inclination adjusting mechanism that adjustsan inclination of the inclined plate to the base so as to uniform thegap between the end surface of the magnetic body and the inner surfaceof the side wall, the inclination adjusting mechanism being disposedbetween the inclined plate and the base.
 6. The metal molded bodymanufacturing apparatus according to claim 1, wherein the end surface ofthe magnetic body of the moving magnetic field generation sectionextends beyond an upper surface of the molten metal put into the diefrom below a bottom of the die.
 7. The metal molded body manufacturingapparatus according to claim 1, wherein the die has a curved shape inplan view, an additional magnetic body member is provided in the endsurface of the magnetic body of the moving magnetic field generationsection, and an end surface of the additional magnetic body member is acurved surface along a curved inner surface of the die.